Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. इंटरनेट मानक “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “प0रा1 को छोड न’ 5 तरफ” Jawaharlal Nehru “Step Out From the Old to the New” “जान1 का अ+धकार, जी1 का अ+धकार” Mazdoor Kisan Shakti Sangathan “The Right to Information, The Right to Live” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 1448-47 (1962): Methods of Test for Petroleum and its Products, Part 47: Knock Characteristics of High Performance Fuels by Extended Motor Method [PCD 1: Methods of Measurement and Test for Petroleum, Petroleum Products and Lubricants]
Transcript
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 1448-47 (1962): Methods of Test for Petroleum and itsProducts, Part 47: Knock Characteristics of HighPerformance Fuels by Extended Motor Method [PCD 1: Methodsof Measurement and Test for Petroleum, Petroleum Productsand Lubricants]
IS : 1448 (Pa+t JJ) - 1962 [P : 471
KNOCK CHARACTERISTICS OF HIGH
FUELS BY EXTENDED MOTOR
(P : 47)
Adapted, with permission, from the Institute of Petroleum
.l. SCOPE
PERFORMANCE
METHOD
Standard No. IP 150160
1.1 This method determines, under relatively severe conditions, characteristics of fuels for use in spark-ignition engines, when
the knock such fuels
rate above 100 motor octane number by P: 26. One particular application is the determination of the weak mixture ratings of fuels intended for use in aircraft engines.
2. TERMINOLOGY
2.0 For the purpose of this method, the following definitions shall apply.
2.1 Extekded Motor Method Performance Number - The whole number given in Table II of P: 45 corresponding to the engine rating determined in millilitres of tetraethyl lead (TEL) in iso-octane.
2.1.1 Ratings of aviation fuels are expressed as Performance Numbers.
2.2 Extended Motor Method Octane Number - The whole number given in Table IV corresponding to the engine rating determined in milli- litres of tetraethyl lead (TEL) in iso-octane.
2.2.1 ‘Ratings of motor fuels are expressed as Octane Numbers.
3. OUTTJNE OF THE METHOD
3.1 The extended motor method rating of a fuel is determined by comparing its knocking tendency- with those of reference fuels of known anti-knock value under the standard engine operating conditions of this method. This is done by adjusting the compression ratio for the sample to obtain standard knock intensity as defined by guide tables and as measured by an electronically controlled knockmeter. The knockmeter reading for the sample is bracketed between those for two reference fuels, and the rating of the sample is calculated by interpolation. The bracketing reference fuels are prepared from Go-octane and TEL.
4. APPARATUS
4.1 The kno&testing unit with detonation meter as described in P : 26 of IS: 1448 (Part I)-1960 shall be used without modification.
40
IS : 1448 (Part II) - 1962 [p : 471
5. REFERENCE MATERIALS
6. OPERATING CONDITIONS
6.1 The following operating conditions are mandatory.
6.1.1 Engine Speed - 900 f9 rpm, constant within 9 rpm, during a test.
6.1.2 Spark Advance - automatically controlled to give :
Degrees At a Micrometer Setting of in.
0.313
17 0.156 16 0.104 15 0.052 14 0.000
6.1.3 Spark-Plug Gap - 0.51 -J&*13 mm (or 0*020f0.005 in.).
6.1.4 Breaker-Point Gap - 0.51 mm (or 0.020 in.).
6.1.5 V&e Clearances - 0.20+0*02 mm (or 0*008+0.001 in.) measured ) with the engine hot and running under standard operating conditions on a reference fuel of 80 octane number.
6.1.6 Crankcase Lubricating Oil - SAE 30 having a kinematic viscosity Oils without detergent additives are
6.1.7 Oil Pressure - 1-s to 2.1 kg/cm2 (or 25 to 30 lb/in.a) under operat- ing conditions.
6.1.8 Oil Temherature-57*0”&8*5”C (or 135”*15”F) with the tem- perature-sensitive element completely immersed in the crankcase oil.
6.1.9 Coolant ‘Temperature - 100~0”&1~5”C (or 212”&3”F). During a test, hold the temperature constant within f0*5”C (or +l”F).
6.1.10 Intake Air Humidity - 3.5 to 4.3 mg of water vapour per gram (or 25 to 30 grams per pound) of dry air.
6.1.11 Intake Air Temperature - 37.8” f2.8”C (or 100” f5”F) as indicated by the mercury thermometer at the carburettor entrance.
41 ,’
IS : 1448 (Part II) - 1962 [P : 471
6.1.12 Mixture Temfierature - 148.9” f I.1 “C (or 300” &P”F) as indicated by the mercury thermometer in the intake manifold.
6.1.13 Carburettor Venturi - throat size dependent on altitude as follows:
Altitude
m W)
0 to 490 (0 to 1 600)
Over 490 to 1 000 (over Over 1 000 (over 3 300)
Diameter of Venturi Throat
mm (in.)
14.29 (9/16) 1 600 to 3 300) 15.08 (19/32)
19.05 (3/4)
6.1.14 Micrometer Adjustment - Set the micrometer to read 0.500 mark when the compression ratio is 5.5 : 1.
6.1.15 Maximum Knock Mixture - At each compression ratio and for each fuel being tested, adjust the fuel-air ratio by varying the carburettor float level in increments until the setting that produces a maximum knockmeter reading is obtained. The fuel level for maximum knockmeter reading shall be between 0.8 and 1.8 in.
NOTE 1 -For some samples it may be necessary to change the size of the metering jet in order to meet this requirement. However, if the requirement is not met when using reference fuels, a thorough check of the carburettor and of the induction system should be made.
6.1.16 Standard Knock Intensity - obtained with a reference fuel under the standard operating conditions of this method and at a micrometer reading corresponding to the TEL concentration and the prevailing barometric pressure, in accordance with Tables I or II or III, and correctionTableIV of P t 26.
7. PROCEDURE
7.1 Starting and Stopping t&e Engine -Before starting the engine or changing to a fuel of unknown knock rating, ensure that the cylinder micro- meter reading is at least O-625. Switch on the ignition while the engine is being motored and set the carburettor to draw fuel from one float-bowl. Before stopping the engine, turn off the fuel and then switch off the ignition and motor the engine for one minute. To avoid corrosion and warping of valves and seats between operating periods, rotate the engine by hand to top dead centre on the compression stroke.
8. OBTAINING STANDARD KNOCK INTENSITY
8.1 With operating conditions stabilized and the carburettor set for maxi- mum knock on a reference fuel, obtain standard knock intensity by ad- justing cylinder height to the appropriate micrometer setting for the reference fuel being used. The object of this preliminary adjustment is to ensure that all fuels are tested at the same knock intensity.
42
licated
1llows :
1 mark
)r each )r float kmeter ,eading
netering et when I system
der the teading Bmetric rble IV
Tine or micro- engine t-bowl. gnition rarping f hand
maxi- by ad- or the nt is to
IS : 1448 (Part II) - 1962 [P : 471
9. ADJUSTING KNOCKMETER AND DETONATION METER
9.1 Zero Adjustment of Knockmeter - Before daily operation, with power and operational switches of the detonation meter in the OFF position, check the zero of the knockmeter. Reset as necessary using adjusting screw provided on the knockmeter face.
9.2 Zero Adjustment of Detonation Meter - With the power switch in the 0.N position, warm up the meter for about 30 minutes. Then with the operational switch in the OFF position, and the METER READING and SPREAD controls in ,their approximate normal operating positions, check the zero of the knockmeter. If adjustment is necessary, remove the screw cap marked ZERO on the detonation meter, and adjust with a small screw driver to bring the knockmeter pointer to zero.
Although the ZERO adjustment of the detonation meter is not critical, it is good practice to recheck it from time to time to compensate for valve aging and after installation of replacement valves and parts.
9.3 Adjustment of Time Constant - The TIME CONSTANT control switch has six positions. Position No. 1 gives the fastest, and position No. 6 the slowest meter response, with other positions being intermediate.
9.4 Adjustments of Detonation Meter Reading and Spread-The controls for METER READING ( marked SENSITIVIT2’” on earlier meters) and SPREAD are both provided with independent coarse and fine adjust- ment and with indices for resetting.
NOTE 2 - If the approximate rating of the fuel sample is unknown, it isrecommended that the initial detonation meter settings be made on &octane reference fuel. Some- times rt will be found necessary, in order to follow the appropriate guide table, to reset the meter controls using a reference fuel with an anti-knock value similar to that of the fuel sample.
9.4.1 With the engine operating under standard test conditions on a reference fuel, adjust the meter reading and spread as follows:
Turn the knobs (fine and coarse) marked METER READI.hfG and SPREAD fully counterclockwise. Turn the coarse knob on the SPREAD dial clockwise approximately 15” and the fine knob approxi- mately 150” ; turn the METER READING coarse knob clockwise so that the knockmeter pointer is approximately mid-scale, and use the fine knob for precise control. Adjust the carburettor float-bowl level to obtain maximum knock. If the maximum is not well defined, turn the SPREAD knobs clockwise until the meter reads 100, then rotate the METER READING knobs counterclockwise until the meter is near mid-scale again.
9.4.2 Change to the carburettor tank containing a second reference fuel with a TEL content which differs from that of the first reference fuel by not more than the amount specified in 12.2 and adjust its float-bowl level to
IS : 1448 (Part II) - 1962 [P : 471
obtain maximum knock. The spread may then be determined by’compar- ing the maximum reading for the two reference fuels. A desirable spread for maximum bracketing limits is 15 to 30 divisions. If the spread is too small, increase the knockmeter reading approximately 20 divisions by turning the SPREAD knobs clockwise; then turn the METER READING knobs counterclockwise to restore the original reading. In some ranges, however, it may be necessary to accept a spread in excess of 30 divisions.
10. CHECKING TEST CONDITIONS
10.1 The engine should cease firing immediately the ignition is switched off. If it does not, operating conditions are unsatisfactory; examine the engine for defects, particularly for combustion chamber and spark-plug deposits, and remedy such conditions before rating fuels.
10.2 It is essential also to check the correctness of engine and test conditions at the anti-knock levels of subsequent fuel samples by using standardization fuels which are available. These are rated in exactly the same way as fuel samples, and their ratings should fall within f0.4 octane number of the values given in the appropriate certified calibration table.
10.3 Once detonation meter controls have been set under standard knock intensity in accordance with 8 and 9, conditions will remain correct during the testing of standardization fuels and fuel samples only so long as no changes are made to these settings. If at any time inadequate or excessive spread requires a readjustment of detonation meter controls, this shall be made according to the instructions in 9 with the engine operating at standard knock intensity on a reference fuel blend.
10.4, A further requirement for correct test conditions is that the micrometer readings shall be within &to*025 of those given in the guide tables (corrected for barometric pressure) for the reference fuel blends which match the fuel samples.
11. ADJUSTING COI\IIPRESSION RATIO AND CARBURETTOR
11.1 Preliminary Adjustmexit of Compression Ratio - Fill one tank of the carburettor with the fuel sample and adjust the fuel level to give approximately maximum knockmeter reading. Then make a preliminary adjustment of the cylinder height to give a knockmeter reading of about 55 scale divisions. As any necessary readjustment of fuel level will increase the knockmeter reading, time can be saved by setting at 52 or in some cases even lower.
11.2 Mikture Adjustment-Adjust the fuel level for the position of maximum knock as follows:
With a setting of the fuel level, for example, of 1.3 on the etched glass scale, allow the knockmeter to reach equilibrium and record the reading for this position. Obtain and record knockmeter readings for
44
npar- pread s too 1s by 3IJvG .nges, IS.
d off. ngine losits,
itions ation s fuel If the
cnock uring 1s no :ssive 111 be tdard
neter ables which
one give
inary rbout rease cases
n-i of
ched 1 the :s for
IS : 1448 (Part II) - 1962 [P : 471
richer fuel-air ratios by raising the fuel level by 0.1 ‘increments to settings of 1.2, 1.1, . . . until the knockmeter reading has decreased at least 5 divisions from the maximum reading recorded. Reset the fuel level at the position for which the maximum knockmeter reading was recorded, for example, 1.2. Starting from this point, follow a similar procedure for weaker fuel-air ratios by setting in turn at 1.3, 1.4 . . . until the knockmeter reading has decreased at least 5 divisions from the maximum reading recorded. Set the fuel level at the position for which the maximum knockmeter reading has been obtained and recorded, or between the two positions for which the same maximum reading was obtained, for example, 1.25. Check at least once that this is the position for maximum knock by taking readings at levels O-1 ,on either side; in the example just given, at both 1.15 and l-35. If higher knockmeter readings are obtained at either of these positions the setting is in error, and the entire procedure shall be repeated. At each setting of the fuel level allow the knockmeter to reach equilibrium before readings are recorded.
NOTE 3 - If a tendency for the sample to bubble or boil in the fuel level sight glass is observed when making the adjustments in 11.2, it is recommended that the carburettor cooling apparatus be used as described in 11.4 of P : 26. For normal conditions, how- ever, carburettor cooling shall not be used.
11.3 Final Adjustment of Compression Ratio -Adjust the cylinder height to give a knockmeter reading of 55f3 scale divisions. Leave this setting of the compression ratio unchanged for the remainder of the test.
12. BRACKETING THE FUEL SAMPLE
12.1 First Bracketisg Reference Fuel - From the micrometer reading arrived at in 11.3 and the appropriate guide table, estimate the probable knock-rating of the fuel sample. Place a leaded reference fuel blend of similar anti-knock value in another carburettor tank and run the engine on this trial blend. Adjust the level of the float-bowl to the maximum knock position as described in 11.2. Extreme care is required to ensure thorough mixing of the ingredients of all blends used in this test procedure. When changing the fuel in a carburettor tank, drain the fuel completely by opening the drain-cock. Permit a small portion of the new fuel to flow through the line before closing the drain-cock. Air bubbles in the system are sometimes indicated by fluctuations in the fuel level or by unstable engine operation; eliminate these bubbles by rapidly opening and closing the drain-cock.
12.2 Second Bracketing Reference Fuel - Select a second trial reference fuel with a TEL content such that the knockmeter reading obtained on the fuel sample will lie between those obtained on the reference fuel blends. Place this second trial blend in the third carburettor tank, and run the engine on this blend while the level of the float-bowl is adjusted to. the maximum knockposition as described in 11.2.
45
the fuel sample shall not differ by more than the following amounts:
RANGE OF‘ KNOCK VALUES PERMISSIBLE DIFFERENCE (ml TEL/3.78 litre of IN KNOCK VALUES
&octane) (ml TEL/3*78 litre of z&-octane)
up to 0.6 0.2 Above 0.6 to 1.0 0.4
>, 1.0 9, 2.0 0.5
9, 2.0 ,, 4.0 1.0
13. OBTAINING KNOCKMETER READINGS
13.1 With the three float-bowls set at the levels giving maximum knock, take a series of knockmeter readings for the fuel sample and for the two reference fuels. In each case allow at least one minute for the engine and the knockmeter to reach equilibrium before the reading is recorded; with some fuels appreciably longer times may be necessary. The following table illustrates the number and sequence of readings which shall be recorded :
FUEL KNOCKMETER READINGS ____-__---_~
123456 7 Average
O+“fu;l TEL/3*78/i/reference 68 - .-- - 66 - - 67
Fuel’ sample - 55 - 54 - 53 - 54
06f ill TEL/3.78/i/ reference U -- 48 - - - 46 47
The rating of the fuel will be valid only if the cylinder height, as measured by the micrometer, is within &O-O25 in. of the corrected setting given by the guide tables.
14. CALCULATION AND REPORTING
14.1 From the averages of the knockmeter readings obtained in accordance with 13 for the fuel sample and for each of the reference fuels calculate the rating of the fuel sample in terms of ml TEL/3*78 litre by interpolation. Obtain the corresponding Octane Number or Performance Number from Table I or Table II of P: 45, respectively.
14.2 Report the result to the ‘nearest integer as the Performance Number Extended Motor Method (PNEMM) in the case of aviation fuels or as the Octane Number Extended Motor Method (ONEMM) in the case of motor
46 I
IS : 1448 (Part II) - 1962 [p :-471
fuels,.. When the figure taken from the conversion tables ends with 0.5, report the nearest even number; for example, report 116.5 as 116, not 117.
15. REPRODUCIBILIT’Y
15.1 Extensive data from different laboratories over a number of years for many samples of conventional aviation fuels have shown a standard deviation of 1.2 performance number. In 19 cases out of 20, therefore, single ratings on a fuel carried out in each of two different laboratories should not differ by more than 3.5 performance number, although repeat ratings in the same laboratory can be expected to agree within I.7 performance
A value with a high probability of being within 3 performance number of the true value for the sample can be obtained only by averaging ratings obtained in a large number-often an impracticably large number of engines all in different laboratories. For instance :
ACCURACY DESIRED NUMBER OF INDEPENDENT TESTS REQUIRED FOR
r------- A --- 90 percent 95 percent 99 percent probability probability probability
Within f3 of true PN 1 1 2 fls5 ,, PN 2 3 5
rtl 2, PN 5 7 12
The above degree of reproducibility applies to conventional aviation fuels when careful attention is given to the details of test procedure and engine condition; it does not necessarily apply to fuels which differ materially from finished aviation fuels, and the reproducibility in such cases is likely to be worse.
The reproducibility of the method when applied to motor fuels has not been established.
IS : 1448 (Part II) - 1962 [P : 471
TABLE I MICROMETER SETTINGS FOR STANDARD KNOCK INTENSITY AT A BAROMETRIC PRESSURE OF 760 mm OF MERCURY
For Use at Altitudes from Sea LevelezE=n (or 1600 ft), 14’29 mm (or 9/16 in.)
TEL IB Iso-
ccr.4NF., ml PP.R
3.78 litre
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
. 2.6
2.7
2.8
2.9
3.0
(Sea Table IV of P : 26 for corrections for other barometric pressure)
I 1 I I I I
0.182 0.179
0.150 ~ 0.148 0.128 i 0.126 0.113 0.112
0.102 0.101
0.094 i 0.093 om9 0.088
0.083 0.082
0.078 ~ 0.077 0.074 0.074
0.070 0.070
0.067 0.067
0,064 0.064
0.062 0,062
0.059 0.058
0.056 0.056
0.054 0.054
0.052 ’ 0.051 0.049 0.049
0.047 0.047
0.045 0.045
0.043 ~ 0.043 0.042 0.042
0.040, 0040
0.038 0.038
:::,'g 1 ,“::,“: 0.033 0.033
0.032 ~ 0.031 0.030 0.030
0.029 , -
0.02 0.03 i 0.04 0.05 i 0.06 j 0.07 / 0.08 j 0.09
Micrometer Setting, in.
0.175 : 0.172 0.145 0.143
0.125 0.123
0.110 0.109
0.100 0.099
0.093 0.092
0.087 0.086
0.082 0.082
0.077 0.077
0.074 0.073
0.070 0.070
0.067 0.066
0.064 0.063
0.061 ~ 0.061
0.058 0.058
0.0513 o’055 0.054
~ 0.053
0,051 0.051
0.049 0.049
0.047 0.046
0.045 ~ 0.045
0.043 0.043
0.041 0.041
0.039 0.039
0.037 0.037
0.036 0.035
0.034 0.034
0.032 0.032
0.031 0.031
0.030 ~ 0.029
0.169
0.141
0.122
0.108
0.098
0.091
0.086
0.081
0.077
0.073
0.069
0.066
0.063
0.060
0.058
0.055
0.053
0.051
0.049
0.046
0.045
0.043
0.041
0.039
0.037
0.035
0.034
0.032
0.031
0.029
48
0.065
0.165 i
0,065
0,162
0.139 0.137
0,120 i 0.118
0.106 0.105
0.098 1 0.098
0.090 0,090
0.085 0.084
0.080 0.080
0.076 0.075
0.072 0.072
0.069 0.069
0.159 ’ 0.156
0.134 0.132
i:;;: i ;::;i 0.097 ! 0.096
0.090 1 0.089
0.084 0.084
0,079 ! 0.079
0.075 ~ 6.075
0.072 1 0.071
0.065 0.065
0.068 oa68
0.063
0.060
0.058
0.055
0.053
0.051
0.048
0.046
0.044
0.042
0.040
0.038
0.037
0.035
0.034
0.032
0.030
0.029
0.063 ) 0.063 0.062
0.060 I 0.060 1 0.060
0.057 ~ 0.057 1 0.057
0.055 1 o.os5 ~ 0.054
0.053
0.050
0.048
0.046
0.044
0.042
0.040
0.038
0.037
0.035
0.034
0.032
0.030
0.029
0.053 0.052
0.050 i 0’050
0.048 0.048
0.046
0.044
0.042
0.040
0.038
0.037
0.046
0.044
0.042
0.040
0.038
0.037
0.035 0.035
0.034 , 0.034
::::: ~ :::::,
0.029 1 0.029
I
0.153
0.130
0.114
0.103
0.095
0.089
0.083
0.079
0.074
0.071
0.067
0.064
0.062
0.059
0.057
0.054
0.052
0.049
0.048
0.045
0.043
0.042
0.040
0.038
0.036
0.035
0.033
0.032
0.030
0.029
-
TEL IN Iso-
XTANB, ml PER
3.78 litre
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
IS : 1448 (Part II) - 1962 [P : 4:
TABLE II MICROMETER SETTINGS FOR STANDARD KNOCK INTENSITk AT A BAROMETRIC PRESSURE OF 760 - OF MERCURY
For Use at Altitudes from 499 m to 1000 m (or 1600 to 3 300 ft), 15’08 mm (or 19/32 in.) Venturi
(See Table IV of P : 26 for corrections for other’barometric pressures)
